Natural Laws and Car Control Chapter 5 Natural Laws and Car Control

Key Terms Inertia Momentum Energy of motion Gravity Friction Traction Tread Blowout Force of impact Active restraint device Passive restraint device Vehicle balance Center of gravity Pitch Total stopping distance Perception time Perception distance Reaction time Reaction distance Braking distance

Energy of motion/gravity Inertia/Momentum Energy of motion/gravity An object at rest stays at rest and an object in motion tends to stay in motion unless…? Imagine you are the passenger in a vehicle, what would happen to your body if the driver suddenly slammed on the brakes? Accelerates? Goes around a curve? Momentum is the tendency of an object to stay in motion… The amount of momentum an object has depends on what?? Speed and weight determine a vehicles energy of motion. Look at figure 2 on page 165…discuss… Gravity is the force that pulls all things to earth. What goes up must come down! How does this effect your vehicle?

Tires and Traction The force that keeps a tire from sliding on the road is________ _______ makes it possible for your vehicle to grip the road so you can control speed and direction. The grooved surface of a tire is called ________ _____ provides the traction for starting, stopping, and gripping the road. Grip will depend on the type of weather condition as well as the condition of your tires.

Inflation and Traction Discussion Points Did you know?? Under inflation Over inflation Temperature Refer to figure 4 on page 167 Ensuring good traction(page 168) Vehicle condition Road condition Driver action “TIRE PRESSURE- you cant tell just by looking if your tires are properly inflated. A tire that is underinflated by 40% can look just like a properly inflated tire.”

Curves play a huge role while driving Balance and Control Discussion Points  Curves play a huge role while driving Vehicle balance Center of gravity (figure 5, page 170) Stability Male vs. female(center of gravity is different) Shorter person vs. larger person Small vehicle vs. big vehicle Pitch, roll and YAW! Figure 6 on page 171 Sharpness of curve Speed Load Shape of road Figure 7 for quick discussion Remember: Your car is always wanting to stay in a straight line because of inertia, so don’t forget to turn!!!

Stopping Distance Must know vocab! Discussion Points Perception time Perception distance Reaction time Reaction distance Braking distance P.D.+ R.D.+B.D.= TOTAL STOPPING DISTANCE Vocabulary Figure 8 on page 173 Figure 9 on page 174 Factors that affect braking distance Driver ability, speed, vehicle condition, roadway surface, hills and weight

Controlling force of impact Factors for force of impact Safety belts Speed Weight The heavier a vehicle, the damage it will cause Time between impact and stopping Active restraint device Passive restraint device Click it or ticket!

Air bags Other Protective Devices Crush zones Energy-absorbing bumpers An air bag is a balloon type device that automatically inflates to protect you. Other Protective Devices Types of air bags Frontal air bags Side air bags Air bags are meant to be used with safety belts Keeping your hands at 8 & 4 or 9 & 3, will offer a balanced hand position for good steering control and will help prevent injury if the air bag deploys Child safety (figure 12 on page 177) Crush zones Energy-absorbing bumpers Side-impact panels Penetration- resistant windshields Head restraints